Semiconductor sensors based on p-i-n diodes have been widely adopted as particle counters and as particle energy measuring devices (spectrometers) with high resolution. Their operating principle is based on the fact that a charge induced in the counter's substance is collected on the electrodes when an ionizing particle is passing through the sensor (sensing element).
Important feature of semiconductor counters is their small size. It has strongly extended the possibilities for application of these detectors not only in the area of experimental physics but also in the engineering—in devices for process control and in medicine.
A p-i-n-diode silicon, low-noise detector by the planar technology (Kemmer J. Fabrication of low noise silicon radiation detectors by the planar process//Nuclear Instruments and Methods.—1980.-V.169.-P.499-502.) and its further development (patent for invention U.S. Pat. No. 4,442,592) is known in the state-of-the-art. These papers disclose the methods for manufacture of detectors by the planar technology for radiation detection, which have semiconductor p-n junctions. However, the disclosed embodiments of the planar semiconductor diodes are different.
A semiconductor detector for X-ray and low-energy gamma radiation detection (patent for invention of the Russian Federation No. 2248012, IPC: G01T1/24, H01L31/1 15), made of monocrystalline silicon and containing a flat signal p+-n junction, around which there are circular guard p+-n junctions with electrodes and a preamplifier, the electrode of the flat signal p+-n junction being connected to the preamplifier input, and the electrode of the inner circular guard p+-n junction being connected to zero potential bus of the preamplifier is the closest to the technical solution applied for.
The invention resolves a problem of improvement in the overall performance of the device by draining the stray current of the guard ring for improvement of the energy resolution and contrast range of the measured energy spectrum. However, the apparatus is intended for detection of the X-ray and low-energy gamma radiation only. For sensitivity enhancement and high rate of detection of the whole spectrum of the ionizing radiation (except for the neutron one), it is necessary to increase the volume of a semiconductor to boost the probability of hitting and dispersion, for example, a gamma-quantum in it and accordingly to increase the rate of counting the radiation flux particles.